The president’s party almost always suffers in the House
Midterms are less than a year away so it’s time to look back at the record.
In the House, the president’s party has lost seats in all but four midterms since 1862, and one of those, 1902, was a year the House expanded so the Republican gains fell short of Democratic gains that year. After 1934 it wasn’t until 1998 that the president’s party gained seats, then the rare event repeated in 2002. Not since.
This regularity over 160 years is hard to attribute to the circumstances of the moment. Likewise the hope that “this year will be different” has been a forlorn one. The size of the seat loss, on the other hand, has varied considerably and is correlated with presidential approval (Clinton in 1998 and Bush in 2002 were unusually popular, as was Roosevelt in 1934) and the state of the economy. Popular presidents lose fewer seats, unpopular ones more. Good times go with smaller losses, bad times with greater losses.
In 2026 we will have the unprecedented circumstance of a large number of mid-decade redistricting decisions as the parties battle to see who can gerrymander the most seats to their advantage. That landscape is still being painted.
In the Senate the pattern of losses are much less dependable than in the House. The president’s party usually loses seats, and the gains have been small since the 1940s. The vagaries of which seats are up and how many for each party adds uncertainty to the Senate picture. And, of course, prior to 1913 the Senate was not elected by popular vote.
In the House, the second midterm for a president produces barely grater losses than the first midterm (an average of 28.9 in the second, versus 24.9 in the first.) There isn’t a “six-year itch” on the House side. The Senate has been a different matter, with second midterm losses averaging 6 seats rather than 2 in the first midterm (since 1946.) One plausible explanation for the Senate is that the 6th year is the reelection of a Senate class elected with the president for his first term. To the extent a winning first term president brings along some partisan companions, they run without his coattails 6 years later. The table shows the seat changes and the averages since 1946.
Next year there will be inevitable discussion of whether 2026 is Trump’s second midterm. Obviously it is in one sense. But for the Senate, this will be the class elected with Joe Biden in 2020, not the class elected with Trump in 2016. This group had mild pro-Democratic national forces either helping or hurting them in 2020. Given this difference in the election cycle, the average 6 seat loss may not be as good a representation of expectations for Senate seats in 2026.
Here is my look at the pre-election polling, as of Nov. 5, 2022.
The raw polling data is from FiveThirtyEight.com, who generously allow download of their polling database. The trends are my estimates and not those of FiveThirtyEight or anyone else.
I include both LV and RV poll results because I believe this reflects uncertainty about turnout, which most do not include in their estimates.
Note the trends as well as the point estimates. The last date of polling is shown in each chart, but most polling was completed a week or more before the election.
Charts are in order of Cook rating of the race and alphabetical within Cook rating (so Solid-D to Solid-R and alphabetical within rating group.
A race had to have at least 5 polls to be included here.
The congressional generic ballot is one of the few indicators with a long history of non-presidential vote outcomes we have. I’ll look at how good a predictor it is at another time. Here is simply a review of the trends over each election cycle. The chart above shows each cycle since 1999-2000 until the current cycle, as of Oct. 5, 2021.
And for the obsessive, here is a chart of each cycle since 1945-46. It Is unreadable without zooming in, so download it and zoom as you wish.
Hmmmm. I wonder what this is about? (OK: tl;dr it is about midterm elections and what to expect in 2022).
“Surge and decline” is the title of a 1960 article by Angus Campbell:
Abstract
The tides of party voting are as fascinating as the fluctuations of economic activity. Regularities in the ebb and flow of voting with the alternation of Congressional and Presidential elections challenge the analyst to find an explanation. This article seeks it in propositions rooted in survey data.
Campbell’s explanation was that presidential elections are largely driven by “short term forces” that provide a temporary advantage to one party, usually the winner of the presidency. Then in the midterm, with no presidential election, short term forces are less important and the electorate shrinks with lower turnout (a “low stimulus election” relative to presidential) and the “long-term force” of partisanship becomes relatively more dominant in the midterm. The result is a return to the partisan balance after the surge favoring the presidential winner two years earlier.
This is a beautifully elegant theory. It is rooted in a simple model of partisanship, short-term forces and the inevitable decline of turnout in midterms. I love it.
Alas, it no longer commands general acceptance as a theory of midterm seat loss. More emphasis is now given to presidential approval, economic conditions and incumbency. Those theories bring substantial empirical evidence, and are certainly sensible. But to me they lack Campbell’s beautiful simplicity.
I’m not here to argue theories of midterm loss, but rather to simply illustrate the votes side of midterm losses. That the president’s party almost always loses house seats in midterms is a fact. Here I look at the decline in votes for the president’s party from presidential to midterm.
For fun, I’m going to walk you through the puzzle and steps that end with the figure at the top of this post. Here is the first step. What IS this??
As my poor former students know, I enjoy starting a class example with a mystery. Show the chart above, invite speculation as to what it might be. I love this one because it looks like random noise with no relationship at all.
Next step: Revealing the variables.
OK here are the variables. National Democratic percentage of the 2-party House vote in the midterm by the national 2 party vote in the previous presidential election. Not much of a relationship. Some votes go up (above the diagonal) and about as many go down (below diagonal.)
Ahh, but what about control of the presidency? The midterm-loss of seats by the president’s party is well known. The national vote, here, shows the same pattern. Dems do better (above diagonal) with GOP president, and do worse with a Dem president, almost always (except 2002.)
This is the surge and decline of votes. Almost always the president’s party wins a smaller share of votes in the midterm than they did in the presidential year. Not surprisingly, fewer votes translate into fewer seats, but that’s not our topic here. For that see this post.
The pattern is clear if we fit a regression for midterms with Rep presidents (red line) and one for Dem pres (blue line). Now the upward slope is clear (midterm performance IS related to prior pres vote) and the party of president shifts the lines up (Rep pres) or down (Dem pres).
FWIW the red and blue lines are nearly parallel. A test of a pooled model finds the difference in slopes to be statistically insignificant (p=.9465). I’m using the separate regressions here, but there would be minimal difference for a pooled model.
So what does the model tell us about, say 2018? The red line estimates the Dem 2-pty vote in 2018 to be 53.1%, up from the Dem 2-pty 2016 vote of 49.5%. In fact, Dems got 54.4%, 1.3 points better than the model and 4.9 points over their 2016 performance.
We don’t know how Dems will do in 2022, but we do know how they did in 2020 and that there is a Dem president. The vertical black line shows the actual Dem share of 2020 House vote, and the blue arrow shows the fit: a predicted 47.8% in 2022, down from 51.6% in 2020.
This is the dilemma of every presidential party: they are almost certain to lose votes in midterm elections. For closely divided congresses (looking at you 117th) this imperils majorities. 2002 was an exception, with 1998 and 1990 almost being exceptions.
How do votes translate into seats? The relationship shifted after 1994 undoing a long standing Dem advantage. The votes-to-seats model expected Dems to hold 50.6% or 220 seats in 2021 (actual post-election was 222). For 2022 the estimate is 45.0% of seats. That would be 196 seats, a loss of 26 from the post-2020 election total.
The president’s party gained house seats in 1934, 1998 and 2002, and lost share of seats in every other midterm since 1862. Reps gained seats in 1902 as the House expanded but actually lost share of seats as Dems gained more that year.
If the historical pattern applies in 2022 the Democrats are unlikely to hold control of the House. In addition there will also be the effect of redistricting. Both parties will have an incentive to gerrymander for every advantage possible where they control the process.
Of course the past pattern may change. Political skill or folly might shift the balance away from the models. The model is useful because it gives us a basis for our expectations. We can judge party performance by whether outcomes exceed or fall short of model expectations. 12/12
I’ve been shocked to hear several sources I respect get the midterm seat loss story wrong. So here is my effort to clarify.
The president’s party almost always loses House seats, but there have been 4* exceptions since 1862: 1902, 1934, 1998 & 2002. *HOWEVER in 1902 the House expanded so while Reps gained seats Dems gained more, thus Reps won a smaller percentage of seats that year. So the presidents party has lost strength in all but 3 midterms since 1862.
In the Senate the president’s party usually loses seats, but not as reliably as in the House. There have been 6 exceptions since 1960.
There is little difference, on average, in House seat losses in 1st vs 2nd midterms. An average -26.4 in 1st and -28.1 in 2nd. NO SIX YEAR ITCH! NO 1ST MIDTERM CURSE EITHER, for that matter.
2nd midterms HAVE been worse in the Senate: -2.3 in 1st, -6.0 in 2nd.
So PLEASE stop saying the president’s party only gains seats “once in the last 100 years”– you know who you are. The right answer is “three times in the last 100 years.”
And don’t imply the Senate is as predictable as the House. They aren’t the same.
And… 1st term vs 2nd? Nah. This is another rant as many people bring up “first midterm” (and in a 2nd term almost always talk about the “second midterm”) as if that mattered. It doesn’t, on average. It does vary across presidencies with some bigger losses in 1st and some in 2nd midterm.
And will 2022 be different? I don’t know. But we should get the history right.
Data details
These seat changes reflect the immediate outcome of the November election. Sometimes members die, change party or resign before the Congress is sworn in, and of course changes can occur during the Congress.
Brookings hosts Vital Statistics on Congress. Note they have a typo for 1998 indicating a loss rather than a gain. I use them here with that fix
